1. Field of the Invention
The invention relates to endoluminal therapy, and, in particular, to methods and devices for securement of hollow organs, including gastric restriction procedures in the stomach for treating obesity and gastroesophageal reflux disease (GERD).
2. Description of the Related Art
Flexible endoscopic therapy of the hollow organs such as the stomach, intestines and esophagus has been shown to have fewer complications and faster recovery times than traditional or laparoscopic surgery. As such, there is a growing interest in expanding the capabilities of such therapy. In particular, there is a desire to perform organ modification, for example gastroplasty, from within the lumen of the organ through a trans-luminal route using flexible endoscopic tools.
Until now, there have been no practical devices available to enable procedures such as endoluminal plasty in a safe and reliable manner. The most challenging part of such a procedure is the placement of durable securement elements, such as sutures, through the full thickness of the organ walls in order to secure portions of the organ together or to attach elements to the wall. The reason securement element placement is challenging is that the organ wall may consist of multiple layers, each having unique physical properties. For example, the stomach has three primary wall layers including an innermost layer is the mucosa, the middle layer is the muscularis, and the outermost layer is the serosa. The mucosa is a relatively fragile layer and is loosely connected to the muscularis. The mucosa typically comprises a plurality of folds, called rugal folds, or rugae, which make the thickness of the mucosal layer highly variable and unpredictable. Securement elements anchored in the mucosa have been shown to pull out over time. The muscularis is somewhat tougher; although securement elements placed there may still pull out over time if they are placed under tension, as is the case for gastroplasty. In the stomach, the serosa layer is thin but is the toughest of the three layers. It is believed that to create durable securement of the stomach wall, securement elements need to pass through the serosa. This presents a challenge for endoluminal therapy, however, since the combined thickness of the three layers of the stomach wall is normally unpredictable.
In order to deploy a securement element that consistently passes through an ideal layer of an organ wall, the length of the securement element or the depth of deployment needs accurately engage the desired layer. When the desired layer of a wall is the outermost layer, surrounding structures may be in danger of being engaged by such securement element or deployment device.
There is therefore a need for devices and methods to safely and reliably deploy securement mechanisms to a desired layer of the organ wall without endangering surrounding structures.
Another challenge of endoluminal devices intended for use in organ therapy is the engagement and movement of regions of the organ wall in order to approximate and secure multiple locations. Existing endoscopic tools for grabbing, such as grasping forceps, tend to engage only the innermost layer, the mucosa in an exemplary organ, the stomach. It may require a significant amount of force to move a region of the organ wall, pulling by the innermost layer may tear it. A more reliable method of moving the wall is to engage other layers. Further, the process of approximating two regions of the wall may require multiple instruments.
There is, therefore, a need for methods and devices to approximate multiple regions of the wall within a hollow organ, and specifically to selectively engage the muscularis within the stomach wall. There is a further need for instruments that combine the above steps of engaging, approximating and securing multiple regions of the wall of a hollow organ, such instruments being further refined to enable a specific endoluminal procedure such as gastroplasty.
In an organ, it may be desirable to modify the flow rate or pressure of materials or fluids that propagate through the organ's lumen.
There is thus a need for methods and devices to create a restrictive outlet to a luminal pouch from within the lumen of the organ.
Organ wall approximation and restrictive outlet performance may diminish over time as the organ wall dilates due to luminal pressure.
There is, therefore, a need for methods and devices to reduce the amount of permanent dilation that an organ wall undergoes following modification procedures.